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|OTHER THEORIES ABOUT THE K-T EXTINCTION
While an asteroid impact may be cause of the K-T extinction, there are other theories about the cause of that mass extinction. Some of these other theories include:
- Extreme volcanic activity and the accompanying acid raincould have changed the Earth's climate enough to trigger a mass extinction. The late Cretaceous was a time of high tectonic activity and accompanying volcanic activity . The supercontinent Pangaea was splitting up and the continents were taking on their modern-day forms. Extreme volcanic activity would spew dust and acidic chemicals (like sulphuric acid) into the atmosphere, causing global cooling, and perhaps, mass extinctions.
- Changes in the Earth's orbit that could have caused climactic cooling might have caused the extinction. In this scenario, the dinosaurs couldn't adapt to the cold, but the furry mammals could. This is consistent with the climate in the late Cretaceous; toward the end of the Cretaceous, there was a drop in sea level, causing land exposure on all continents, more seasonality, and greater extremes between equatorial and polar temperatures.
- Mammals eating dinosaurs' eggs has been suggested as a cause of the K-T extinction. This doesn't explain why so many other species went extinct, or why there are chemical anomalies in the K-T layer.
- Large amounts of methane changing the Earth's atmosphere (causing a greenhouse effect). The methane source would be from deep-sea algae deposits and/or from plant-eating dinosaurs digestion by-products.
- The herbivorous dinosaurs' over-foraging and the carnivorous dinosaurs' over-culling of the herbivorous dinosaurs could have triggered mass starvation.
- A nearby supernova (an exploding star) could have bathed the Earth in deadly radiation.
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